In recent years, various types of portable personal computers, such as notebook personal computers, have been developed. Most of the portable personal computers have a multi-display function. The multi-display function is a function of displaying screen images on, for example, two displays, respectively.
In a system supporting the multi-display function, for example, two regions are allocated to a virtual screen, and screen images corresponding to the two regions are displayed on two displays, respectively. In addition, in the multi-display function, a so-called “clone display” mode, in which the same screen image is displayed on two displays, is prepared.
In usual cases, however, in the “clone display” mode, the upper limit of the resolution of a displayable screen image is restricted to the resolution of that one of the displays, which has the lower resolution. For example, when the “clone display” mode is used in an environment using two displays such as a low-resolution internal display provided in a portable personal computer and a high-resolution external display, only a screen image having a low resolution that is equal to the resolution of the internal display can be displayed on the external display. Thus, the actual capability of the high-resolution external display cannot effectively be utilized.
In addition, recently, computers including touch panel displays have been developed. In the computer including the touch panel display, various events for controlling an application window or the like, which is displayed on the touch panel display, can be generated in accordance with a user's touch operation on the touch panel display.
A pointing device, such as a mouse or a touch pad, functions as a relative pointing device, with which a pointing position (cursor position) on the screen is moved in accordance with the movement of the pointing device. On the other hand, the touch panel display functions as an absolute pointing device, and a touch position itself on the touch panel display corresponds to a pointing position on the screen.
Jpn. Pat. Appln. KOKAI Publication No. 2009-140471 discloses a digital video camera including a touch-panel-type display. This digital video camera has a function of causing the touch-panel-type display to function as a touch pad when an external monitor is connected to the digital video camera.
In the technique of KOKAI Publication No. 2009-140471, however, the touch-panel-type display is merely used as a substitute device for a touch pad. It is thus difficult for the user to understand the relationship between a coordinate position on the touch panel and a coordinate position on the external monitor. In order to understand the relationship between a coordinate position on the touch panel and a coordinate position on the external monitor, the user is required to frequently move the view point between the touch panel and the external monitor.